I do not understand well abouㅅtKorean language,exactly, but i will try to explain about it …

Saya means I in Korean languange using 나는 (nanen) if you talk to somebody as old as you or younger than you

Saya , 저는 means I using if you talk to somebody older than you or somebody that you respect to ( if you talk to your father or your brother, your teacher etc)

Kamu mean You – 당신을 using in book only ( i think) because if people talk each other they call someone names for example …. How are you ? in Korean language you can say 안녕하십니까 (annyoenghasimnika) or zahra시 안녕하십니까 ?